In a silver halide photographic element, a color image is formed when the material is exposed to light and then subjected to color development with a primary amine developer. The color development results in imagewise reduction of silver halide and production of oxidized developer. The oxidized primary amine developer subsequently reacts with one or more incorporated dye-forming couplers to form dye in an imagewise fashion. Some couplers, referred to as DIR couplers, release a development inhibitor compound or fragment upon coupling with the oxidized primary amine developer. Further, some of these DIR couplers release the inhibitor compound or fragment with a time delay. These are sometimes referred to as DIAR couplers.
A variety of magenta dye-forming coupler types have been used in color photographic materials. 2-Equivalent pyrazolone magenta dye forming couplers are known. Couplers are 2-equivalent where they require a total of 2 moles of silver to be developed to produce 1 mole of dye. Such couplers are advantageous over similar 4-equivalent couplers in that more dye is produced from the same amount of developed silver.
The dyes that are formed by any color coupler during processing have a tendency to fade over time particularly as a result of exposure to light as well as heat and humidity. As all three image dyes of a typical color element fade, this results in overall fading of the image over time. In addition, since the three image dyes may not fade at the same rate, an apparent change in image color also results. Such change is particularly noticable in the case of magenta image dye fading.
Stabilizers are classes of compounds which reduce the foregoing image dye fading problem. Such stabilizers include phenols, bis-phenols, blocked phenols, blocked bis-phenols, metal and other organic complexes and other compounds, all of which have been described for use in conjunction with various color couplers. Photographic elements containing color coupler and stabilizer combinations are described, for example, in EP 0 298 321; EP 0 231 832; EP 0 161 577; EP 0 218 266; U.S. Pat. No. 3,043,697; U.S. Pat. No. 3,700,455; Kokai JP 62043-641, JP 01137-258, JP 01144-048; U.S. Pat. No. 4,782,011 and U.S. Pat. No. 4,748,100.
It is desirable then, to provide a photographic element with a 2-equivalent pyrazolone magenta dye forming coupler, but in which the image dye formed from that coupler will have relatively low fading, particularly when exposed to light.